Hey @ToxicFi7h, this sounds like a problem with your code rather than n8n. From taking a look at the Node.js documentation you probably want to do something like this:
const url = require('url');
let params = new url.URLSearchParams('abc=foo&def=%5Basf%5D&xyz=5');
Also, the Function Item node would need to return a JSON object, for example by running something like this:
return {
myParameter: params.get('abc')
};
Here’s an updated workflow doing the trick:
Result:
Hope this helps!